#include <cstdio>
#include <vector>
#include <cstring>

using namespace std;
long long nr,i,j,n,m,y,x;
vector<long long> G[100004];
bool sel[100009];

void load()
{
  scanf("%lld%lld",&n,&m);
  for(int i=1;i<=m;++i)
  {
    scanf("%lld%lld",&x,&y);
    G[x].push_back(y);
    G[y].push_back(x);
  }
}

void df(int x)
{
  int i;

  sel[x]=true;
  for(i=0;i<G[x].size();++i)
  if(!sel[G[x][i]])
  {

    df(G[x][i]);
  }

}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

  //  scanf("%lld%lld",&n,&m);

    load();
    nr=0;

   // memset(sel,0,sizeof(sel));
    for(i=1;i<=n;++i)
    if(!sel[i])
    {
      ++nr;
      df(i);
    }

    printf("%lld\n",nr);




    return 0;
}